First responders, such as fire fighters, police, or HAZMAT personnel, many times arrive at the site of an emergency situation without the ability to detect environmental hazards such as toxic industrial chemicals, chemical warfare agents, or radiation. Such inability may result in physical harm to the first responders and other responders that follow. Large quantities of toxic industrial chemicals may be present in populated areas: industrial sites, storage depots, transportation and distribution facilities, resulting in the potential for accidents such as the accidental release of methylisocyanate in Bhopal, India in 1984. Other toxic industrial chemicals, for example, include ammonia, chlorine, hydrogen chloride, and sulfuric acid. Chemical warfare agents are usually more lethal than toxic industrial chemicals. Nerve agents are the most common chemical warfare agents, such as the nerve agent Sarin that was used in the 1995 Tokyo subway gas attack. Other chemical warfare agents, for example, include Tabun, sulfur mustard, and hydrogen cyanide.
Chemical warfare agents typically are medium to high volatility and therefore may be detected in the gas phase. Electronic monitors for chemical warfare agents are based on electronic detection using ion-mobility-spectrometry, photo-ionization and flame-ionization. These tools offer a broadband response with high levels of sensitivity, but most suffer from interference effects caused by what is often a highly complex chemical background mix at the scene, and most commercial tools exhibit high false-positive responses to contaminants. Furthermore, these devices are not designed to be wearable, and most tools, although handheld, are relatively bulky and fully engage the user, thereby detracting from other important duties.
Known colorimetric methods for detecting such chemical and biological hazards include simple color-change badges generally having a life span of approximately 8 hours, to tubes providing quantitative data with high specificity, but both require the user to assess the color change to determine the hazard level. Furthermore, gas tubes are sensitive to physical abuse and are limited in some cases to only one or in other cases a few hazards requiring the user to know what type or types of hazards are suspected.
Radiological threats have become more relevant with the so-called ‘dirty bomb’, which combines explosive blast with surreptitious ingredients of radionuclides such as Cs-137, a beta and gamma emitter. Radiological monitors (dosimeters) have been available for many years, mostly for occupational safety monitoring. Pager style, wearable units, having audio/visual alerts built-in are available for such monitoring. Also, a variety of miniature radiation detectors exist, such as small Geiger-Muller tubes, selective scintillation layers with photo-sensors, and silicon diodes. Probes can be attached to other types of monitors, covering any of the radiation species, but these monitors are at best hand-held, and must be maintained regularly. Recently, calorimetric badges that detect radiation have been developed; however, these require the user to constantly monitor its status.
The idea of using interchangeable sensor elements for colorimeter detection has been used for water/soil testing, health monitoring, and a wide range of medical testing and analysis applications. However, known calorimeter systems employing interchangeable sensors are not capable of use in a wide range of colorimetric applications, particularly portable applications requiring a single lightweight calorimeter device. Many calorimeters require a PC, spectrometer, or other similar equipment to produce and/or process a colorimetric reagent. Operating these colorimeters is very difficult, requiring constant user interaction to complete the colorimetric detection process whenever a colorimeter measurement is made. These calorimeters require complex recalibration procedures, often involving multiple measurements using one or more sample reagents, each time a different sensor element is used.
Furthermore, existing calorimetric sensor elements that are interchangeable have little or no capability to store reagent related data on the element, and therefore are inherently limited in use to a narrow range of calorimetric applications. Colorimeter devices used for water testing or urinanalysis can use a number of different test strips, each strip containing reagents targeting different substances. But these sensor elements would not be functional if a different set of reagents was deposited on the element. Any change in configuration to the sensor element would require an associated change to the calorimeter detection firmware.
Some calorimetric, and non-colorimetric, systems employ interchangeable elements with embedded calibration data on the sensor element. But these devices have dedicated hardware to read the data using a process unrelated to that used to read the actual calorimetric data, therefore incurring significant increases in cost, size and overall complexity.
Accordingly, it is desirable to provide a universal card that may be interchangeably used in a low cost, low power electronic device for detecting the presence of environmental agents and transmitting the results to the user and others without disrupting from the user's duties. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.